The present invention relates to a method of connecting a flat cable for use in, for example, wiring in electric apparatus and automobiles, and a terminal.
As shown in FIG. 6, a flat cable 1 comprises flat conductors 1a insulated with an insulation 1b in the form of a tape, while a terminal 3 has cramp pieces 3a projecting on the opposite sides thereof.
Conventionally, the flat cable 1 and the terminal 3 are connected as follows: As shown in FIG. 6, the cramp pieces 3a are stuck through the insulation 1b on the opposite sides of an intended flat conductor 1a so that more than 50% of their length may project from the insulation 1b. Then, the end portions of the cramp pieces 3a that have been stuck through the insulation 3a are bent inward as shown by a broken line. The insulation 1b is broken with the ends of the cramp pieces 3a, so that the cramp pieces 3a come in contact with the flat conductor 1a. 
However, in this connecting method, depending on the length by which the cramp pieces 3a project from the insulation 1b and the way in which the cramp pieces 3a are bent, it may be difficult to break the insulation 1b with the ends of the cramp pieces 3a to thereby bring the cramp pieces 3a in contact with the flat conductor 1a. In that case, stable connection is not obtained.
An object of the present invention is to provide a method of connecting a flat cable and a terminal in which a flat cable and a terminal can always be connected in a good and stable state.
Another object of the present invention is to provide a method of connecting a flat cable and a terminal in which a flat cable and a terminal can be connected in a stable state and a cramp piece is bent into an intended shape easily.
The present invention is to improve a method of connecting a flat cable and a terminal in which a flat cable comprising a flat conductor insulated with an insulation in the form of a tape and a terminal having a cramp piece are connected by sticking the cramp piece through the flat cable at a place corresponding to an intended portion of the flat conductor, and bending the cramp piece that has been stuck through the flat cable, toward the flat conductor to clamp the flat cable.
The method of connecting a flat cable and a terminal according to the present invention is characterized in that an end portion of the cramp piece is made to project from the flat cable by a length that is in the range of 50xcx9c5% of the length of the cramp piece, and then the end portion of the cramp piece is bent.
Also, the method of connecting a flat cable and a terminal according to the present invention is characterized in that an end portion of the cramp piece is made to project from the flat cable by a length that is in the range of 50xcx9c5% of the length of the cramp piece and then the end portion of the cramp piece is bent; and the cramp piece is connected with the flat conductor at a first place where the cramp piece has been stuck through the flat conductor and a second place where an inner surface of the end portion of the cramp piece that has been bent is in contact with an outer surface of a bent portion of the flat conductor that has been bent.
When the end portion of the cramp piece is made to project from the flat cable by a length that is in the range of 50xcx9c5% of the length of the cramp piece and then bent as described above, the flat cable and the terminal can be connected in a good and stable state not only at a first place where the cramp piece has been stuck through the flat conductor but also at a second place where the inner surface of the end portion of the cramp piece that has been bent is in contact with the outer surface of a bent portion of the flat conductor. Especially at the second place, the contact is very stable, and therefore, the connection is highly reliable, because it is formed in a manner that the inner surface of the end portion of the cramp piece that has been bent is in contact with the outer surface of the bent portion of the flat conductor.
When the length by which the end portion of the cramp piece projects from the flat cable is more than 50% of the length of the cramp piece, the connection lacks stability and therefore the reliability of the connection lowers. When the length by which the end portion of the cramp piece projects from the flat cable is less than 5% of the length of the cramp piece, the end portion of the cramp piece is not bent sufficiently, so that the second connection is not formed.
Further, the method of connecting a flat cable and a terminal according to the present invention is characterized in that a terminal comprising a substrate with a window and a plurality of cramp pieces projecting on opposite sides of the substrate is used.
This method of connection ensures that the cramp piece that has been stuck through the flat cable is bent appropriately. As a result, the flat cable and the terminal can always be connected in a good and stable state.